BRA for a very very low formal dress...?

I have a dress that goes down very far and i need to wear a bra, i cannot wear a stick on (as they just fall off) or clear straps (looks bad), i have researched the net and there is the 'Breakthrough' Bra, but it doesnt sell in australia, and no websites have my size, does anyone know of a body corset that has no back or something that i can get in Australia? Thankyou very much!